Well pumping system and related control



Aug. 27, 196s c. N. DEATON WELL PUMPING .SYSTEM AND RELATED CONTROLFiled Aug. 30, 1966 /NVENToR CLAIR N. DEATON ATTORNE United StatesPatent Office 3,398,690i Patented Aug. 27, 1968 3,398,690 WELL PUMPINGSYSTEM AND RELATED CONTROL Clair N. Deaton, P.O. Box 102, Byron, Wyo.

Filed Aug. 30, 1966, Ser. No. 576,131 6 Claims. (Cl. 103-25) ABSTRACT OFTHE DISCLOSURE The present invention relates to new systems for thepumping of uids from wells and in particular relates to control systemsfor preventing hazards and diiiiculties previously experienced fromoverheating of polish rods connecting well pumps with drive mechanisms.

Typically, fluids are pumped from wells, e.g. oil wells, byreciprocating pumps located within the wells which are actuated by drivemeans usually operating through a fwalking beam. The Walking beam isdriven through a Pitman which serves to convert the rotary motion of anelectric motor into reciprocating motion for actuating the well pump.

In such installations the Well pump is connected to the end of thewalking beam by a polish rod (sucker rod or otherV elongated member)which reciprocates through a stuing box that prevents loss of fluid fromthe well. In most wells which require pumping, the pump must have adaily capacity greater than the amount of uids which enter the well fromthe surrounding formations. Under such circumstances the pump will losefluid by sucking the well dry unless the pump is shut down for someportion of each day. This shut-down is most frequently conventionallylaccomplished by the use of timing clocks which are set to permit thepump to operate for -a certain number of hours out of each day. Suchclocks give onlyA an approximate correlation between the amount offluids available for pumping and the length of time the pump operates.Other known techniques include the use of liquid sensing devices on theoutlet of the well which determine when the pump has lost its prime ofliquid and then actuate a timer which restarts the pump `after a presetinterval. (See for example, U.S, 2,550,093 to Smith)V These latterdevices are relatively expensive and because moving parts of the owindicating devices are exposed to the corrosive fluids coming from thewell, such devices are subject to failure.

The present invention exposes no moving parts to the iluids and in fact,need not contact the corrosive well uids in any manner. In addition, thepresent invention permits automatic proportioning of the pumpinginterval to the fluids available for pumping with low cost, highlydependable cont-rol means which, in preferred embodiments, involve nomoving parts whatsoever.

The polish rod in most conventional wells is cooled and often islubricated by the liquid being pumped from the well. If this cooling orlubrication stops, the polish rod will begin to increase in temperaturedue t-o the friction between the polish rod and the packing. The presentinvention utilizes this increase in temperature of the polish rod toactuate a temperature sensing device, which in turn, causesdiscontinuance of the reciprocating action of the polish rod andtherefore of the pump. By utilizing a conventional adjustable rangethermostatic switch, the delay between the discontinuance and theresumption of pumping may be easily varied.

FIGURE 1 is an illustration of a preferred embodiment of the presentinvention.

FIGURE 2 is a detail of the embodiment of FIGURE l showing the locationof the temperature sensing device near the stuffing box.

In FIGURE 1 an electric motor 11 is connected through speed reductionmeans 12, crank 13 and Pitman 14 to one end of the walking beam 15. Theother end of the walking beam 1S is connected to a polish rod 16 whichpasses through a stuiing box 17 and extends downward through the casinghead 18 and the well-bore 1'9 to connect with pump 20 located below thestatic lluid level in the well drilled into luid bearing formation 21. Atemperature actuated variable range switch which opens when exposed to atemperature above a preset value (for example about 150 F.) and closeswhen exposed to a temperature below a Isecond preset value (for exampleabout F.) is inserted into the stuiing box at a point just below thepacking, and is connected by wire 23 to actuate relay 24 which in turncontrols the flow of electricity from the power supply 25 to the motor11. An interval recorder 30 may be inserted in the power line to recordthe times of operation of the pumping unit.

lFIGURE 2 shows the polish rod 16, the stuffing box 17, the temperaturesensing element 22, and its connecting wire 23, together 4with thepumping T 26, and casing head 18, all of conventional design.

To commence operation, manual switch 29 is closed. Because the polishrod is at approximately ambient temperature, relay 4 will be cl-osedpermitting electricity from the power source 25 to energize motor 11.Power is transmitted from motor 11 through reduction box 12, crank 13,Pitman 14 and walking beam 15 to cause reciprocal motion of polish rod16, which in turn, fires pump 20 located in the well-bore. Fluids owfrom pumping T 26 (sh-own in FIGURE 2) and continue to 4flow until thewell has been pumped dry. While the pump is pumping liquid the polishrod 16 is lubricated and cooled by contact with the liquid on thedownstroke. Thus, the friction between the polish rod 16 and stuffingbox 17 is reduced to a minimum. This cooling and lubrication stops whenthe Well has |been pumped dry and the polish rod then begins tooverheat. When the temperature of the polish rod has increased to aboutF. thermostatic switch 22 opens, opening relay 24 and shutting oi powerto motor 11 which stops the reciprocal motion of the polish rod. Thatportion of the polish rod which is located near thermostatic switch 22cools slowly. When its temperature has dropped to about 90 F.,thermostatic switch 22 closes, closing relay 24 and again actuatingmotor 11 and restarting the pumping action. By properly selecting thelower temperature setting of thermostatic switch 22, at which pumping isresumed, the pumping interval of the unit may be controlled so that aproper balance is maintained between the rate of seepage of oil into thewellbore and the hourly capacity of the pump. In any case, overheatingof the polish rod and dama-ge to stuting boxes with the resultingleakage which frequently occurs in conventional systems, can becompletely avoided with the present invention while still withdrawingall of the oil which seeps into the well-bore.

The elevation of pump 20 controls the amount of back pressures exertedby the fluid column in the Well-bore and this elevation can be adjustedin conjunction with the temperature set on the temperature sensingelement 22 so as to optimize production from any given well.

In place of thermostatic switch 22 and relay 24 there can be utilized asingle thermostatic switch with the main power line running directlyinto a thermostatic switch positioned so as to sense the temperature ofthe polish rod 16. This eliminates relay 24. Alternatively, a thermistoror other temperature sensing element may be mounted to sense thetemperature of the polish rod and transmit a signal which eitheractuates a relay or a silicon controlled rectifier or other electroniccircuitry so as to interrupt the current'to motor 11. Still anotheralternate is for the temperature sensing system to modulate the speed ofa variable speed motor, as for example, by conventional siliconcontrolled rectier circuitry which is actuated by a temperature sensingthermistor sensing the temperature of the polish rod. The reciprocalmotion of the polish rod can thus be merely slowed rather thancompletely stopped.

In place of the electric motor discussed above, gasoline yor steam orother conventional power means having suitable control means to permitthem to be slowed or stopped in response to the signal from thetemperature sensing element, c an be utilized.

The circuitry can contain conventional means for compensating for-ambient temperatures so that the cut-off and cut-in points areautomatically raised in hot weather and lowered in cold weather, and thetemperature sensing device can be insulated from radiant heat.

In addition to the oil wells mentioned above, the present invention canlbe utilized on Water Wells, salt brine wells and other air producingwells.

If desired, the minimum interval betwen discontinuance and resumption ofpumping may be controlled by inserting a time delay device into thecircuitry or by the use of conventional clock mechanisms which can beincluded in the recorder 30.

The Word polish rod, as used herein, Should be understood to include anyelongated member which extends through a stuing box and connects a pumpwithin the Well with an external power source. The term stuffing boxshould be understood to mean any sort of gland or seal in frictioncontact with the polish rod. The temperature sensing device may ofcourse, be located on the polish rod, or near the stuffing box, or maybe in a roller which presses against the polish rod, or in any otherposition which permits the sensing of temperature increases in thepolish rod.

Various other variations and modifications to the present invention willbe apparent to those skilled in the art upon a reading of thespecication and all such obvious variations and modifications are to betaken as included within the scope of the claims appended hereto.

What is claimed is:

1. A control system for Well `pumping units having external power meansconnected by a polish rod to a well pump, said polish rod reciprocatingthrough a stuffing box located between said power means and said wellpump when said pumping unit is in operation; said system comprising incombination polish rod control means for slowing or discontinuing thereciprocating motion of said polish rod, temperature sensing meansoperably positioned to sense the temperature of said polish rod, said 4temperature sensing means being connected so as to actu ate said polishrod control means to discontinue motion of said polish rod when thetemperature of said polish rod exceeds a preset maximum wherein thepolish rod is wet by the fluid being pumped and wherein loss of uid fromthe pump increases the friction between said polish rod and saidstuffing box and wherein the polish rod control means is reactuated soas to resume reciprocal motion of the polish rod when the temperaturesensed by said temperature sensing means falls below a presettemperature level.

2. A well pumping system comprising in combination (a) an internal wellpump located in communication with the bottom of said well, (b) powermeans for actuating said internal well pump, (c) polish rod means forconnecting said power means to said internal well pump, said polish rodreciprocating under normal operation of said well pumping system, (d)stufling box means for forming a seal around said polish -rod to preventloss of uid from said well, (e) temperature sensing means responsive tooverheating of said polish rod, (f) polish rod control means for slowingor discontinuing the motion of said polish rod in response to a signalfrom said temperature sensing means indicative of overheating of saidpolish rod wherein ythe polish rod is wet by the fluid being pumped andwherein loss of fluid from the pump increases the friction between saidpolish rod and said stuffing box and wherein the polish rod controlmeans is reactuated so as to resume reciprocal motion of the polish rodwhen the temperature sensed by said temperature sensing means fallsbelow a preset temperature level.

3. The system of claim 1 wherein the Well is an oil well.

4. The system of claim 2 `wherein the well is an oil well.

5. The system of claim 1 wherein the well is an oil well and thetemperature sensing means is located in contact with said polish rod.

6. The system of claim 2 wherein the well is an oil well and thetemperature sensing means is located in contact with said polish rod.

References Cited UNITED STATES PATENTS 1,018,253 2/ 1912 McWilliams etal. 184-6 2,403,688 7/1946- Smith 103-25 2,518,597 y8/ 1950 Brooks103-25 X 2,707,440 5/1955 Long et al. 103-25 2,910,007 10/1959 Buri103--202 2,947,931 8/1960 Hubby 103-25 3,010,401 11/1961y Gramquist 1103-25 3,284,669 11/ 1966 Boyd 103-25 X 3,290,576 12/ 1966 Jensen et al.318--471 WILLIAM L. FREEH, Primary Examiner.

